Cardiovascular disease is the number 1 killer in the United States and much of the Western world. Treatment of the disease costs billions of dollars each year and the costs continue to rise exponentially. Many strides have been made toward improving behavioral patterns that put people at risk, however there is still a need to develop methods to detect disease onset at the earliest possible stage. Early detection requires the measurement of a clinically relevant disease biomarker. One such marker that can be measured is homocysteine. Homocyteine is an amino acid involved in the biosynthesis of methionine and has been clinically linked to cardiovascular disease in a number of studies. Existing methods for measurement of homocysteine require expensive instrumentation, are time consuming, and can only be performed in a clinical laboratory. Advanced Microlabs, LLC is developing microfluidic technology for rapid detection of disease biomarkers that will be inexpensive ($1000 instrument, $5/assay) and require very small samples (1-5 microliters). In the current project, we propose to develop an assay for homocysteine starting from whole blood samples. Our technology platform couples electrochemical detection to microchip electrophoresis to provide the desired low-cost, high portability characteristics. During this project, we wiill develop an assay for both total homocysteine and protein-bound homocysteine using this technology. In addition, we will also develop a second microfluidic device that will allow us to isolate cells from whole blood, a requirement for making accurate measurements. The result of this project will be new techology for the measurement of homocysteine as well as continuous generation of cell free media for analysis.